This is an activity about modeling the effect of wind on a sandy surface. Learners will use trays of sand and straws to recreate surface features of images of Mars. Participants test their ideas about how some of the features on Mars might have been...(View More) produced. This is activity 4 of 9 in Mars and Earth: Science Learning Activities for After School. Note: The Mars image set that is needed to do this activity is on p. 37 of the guide (see Related & Supplemental Resources to the right).(View Less)